In preparing for emergency situations, e.g., caused by either man-made or natural disasters, provisions for an adequate supply of potable water are near the top the list of steps to be taken. A supply of drinking water is considered more important for survival than immediate access to food. The Department of Homeland Security offers guidelines for emergency preparedness, and these guidelines recommend a minimum emergency supply of water comprising one gallon per person, per day, with additional amounts needed for cooking and washing.
The storage of large volumes of water indefinitely can pose problems for many. Storage of tens of gallons of water requires a substantial amount of space. Storage in small containers (e.g., one or two gallon containers, as are commonly available, e.g., in groceries) can require a large number of containers to supply, e.g., an entire family through several days or weeks following a disaster. Larger volume storage, e.g., in typical fifty-five gallon drums, is similarly inconvenient for many householders. A filled fifty-five gallon drum weighs over about 440 pounds and is not easily moveable once filled. Thus, a drum requires dedicated floor space that is structurally capable of holding such weight, and that is close to a water source, e.g., a faucet, for filling. These space considerations alone can make it difficult or impossible for many people to store the recommended amounts of water. Many people lack the space in their homes to keep a large number of these small containers or to keep a 55-gallon drum on hand. In addition to the space concerns, the long-term storage of drinking water can also pose safety concerns if the water is not properly purified upon storage, if the container used is contaminated by a prior use, or if the water is left to stand for years on end.
For these and other reasons, many people do not elect to store the amounts of water recommended for disaster preparedness. Rather, when disaster occurs or is imminent, water, generally from a household tap, is often stored in whatever containers are on hand. Most readily available vessels (e.g., drinking bottles, food storage jars) can contain only a fraction of the amount of water recommended. Thus, there is a need for improved devices for storing potable water.
The largest, strongest vessel readily available to many people is a bathtub. A typical residential bathtub will hold between about 50 and 90 gallons of water, and some will hold substantially more. Storing drinking water directly in a bathtub is not recommended, however, as residue in a bathtub, both from normal use and from cleaning, is likely to cause both microbial and chemical contamination of water stored directly in the tub, making it unsuitable for consumption or food preparation. Use of a bathtub for containing potable water requires a barrier to prevent contact between the water and the bathtub surface.